Air-brake



2 Sheets-Sheet (No Modei.)

- H. L. HOWB.

AIR BRAKBf Patented Sept. 8, 1896.

% e? Y `I. 59 H' y 10.657,476. Patented sept. 8, 1896.

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I INVNTOR wlTNEssEs: i( XM @0. QM

ATTORNEY?.

onms Pzrzws w. P WASHINGTON u c UNITED STATES `PATENT @Erica HENRY L.Howe, or CANANDAIGUA, NEW YORK.

AIR-BRAKE.

SPECIFICATION forming part of Letters Patent No. 567,4"76, datedSeptember 8, 1896.

Application filed July 12, 1895. Serial No. 555,728. (No model.)

To @ZZ whom, t 11i/ay 'coll/cern.' Y

Be it known that I, HENRY-FL. JIIOWE, a citizen of the United States ofAmerica, residing at Canandaigua, Ontario county, State of New York,have invented certain new and useful Improvements in Air-Brakes, ofwhich the following' is a specification.

My invention relates to that class of fluidpressure brakes especiallyadapted for streetcars, but is not necessarily coniined, in itspractical applications, to use with such vehicles.

The invention has for its objects to economize power, as by utilizingthe power stored up in the moving car; to automaticallymaintain apredetermined pressure in the air-reservoir; to effect the applicationof the brakes and the simultaneous restoration of the normal pressure inthe reservoir, thus making the air-supply practically inexhaustible; toprovide in the same apparatus for the restoring of air-pressureindependentlyof the operation of the brakes; to protect the operativeparts of the apparatus from dust; and finally, in attaining` thesedesirable ends,.to lessen the number of parts, simplify the constructionof the apparatus, and enhance its economy of manufacture and durability.I secure these objects by enabling the air pump or compressor, which isoperated-from one of.

the axles of the vehicle, to be entirely disconnected from such axle andcease all movement except when it is desired to apply the brake, or whenthe' air-pressure has fallen below the normal and requires to berestored, or when an excess of pressure is needed, and, by preference,during the act of applying the brakes, by making the act of suchconnection or disconnection dependent upon the degree of air-pressure inthe reservoir, the latter being in direct communication with theconnecting or disconnecting mechanism; by providing means by which theact of applying the brakes will effect or permit the operation of thepump; by providing a means, under the direct control of the brakeman,for causing the air-pump to be at will connected with pump; and byvarious new and improved -employed in every practical application of theinvention, as some of such objects may `be usefully realized without theothers, but I prefer, and shall hereinafterdescribe, a completeair-brake system embodying in one con'- .struction all of the featuresWhich/I have enumerated.

In order to make my invention more clearly understood, I have shown inthe accompanying drawings means for carrying themy into practicaleffect, without limiting my improvements in their useful applications tothe particular construction which, for the sake of illustration, I havedelineated.

In said drawings, Figure l is a diagrammatic View showing certain of theparts in horizontal section of an air-brake apparatus suitable for astreet-car and embodying my invention. Fig. 2 is asectional view on lineII II, Fig. l, of the .stop-cylinder and clutch, constituting the meansfor connecting and disconnecting the air-pump and vehicle-axle. Fig. 3is a section on line III III, Fig.v2, of vsaid clutch. Fig. 4 is asectional view of the air-controlling valves and operating mechanism.Fig. 5 is an end view of a portion of ysuch mechanism. gitudinal sectionof the air pump V or compressor on line VI VI, Fig. 7. Fig. 7 isavertical section of the same on line VII VII, Fig. 6. 1

Referring to the drawings, l indicates a portion of a supporting-axle ofthe vehicle to which the brake system is applied, carried by theusual-wheels, (not shown,) adapted to run on the ground or upon a track:

2 is the driving-shaft of the air pump-or. compressor 3, the latterbeing located at any convenient point, as beneath the floor of thevehicle.

Any suitable connecting mechanismV may be employed to communicate therotation of the axle to the shaft 2, such, for instance, asvsprocket-wheels 4 and 5, ixed,respectively, on the axle and shaft andconnected by a chain 6.

VV-hile any desired form of pump may be `employed in carrying out myinvention, I prefer the improved construction shovvn.{ It

Fig, 6 is a horizontal lon- ICO comprises two cylinders 7, cast togetherand provided with pistons 8,united by connectingrods 9 with theoppositely-arranged or balanced cranks 10 of the shaft 2. These rods arepivoted to the pistons by pins or bolts 11, having bearings in lugs 12cast in the pistons and passing into said bearings and through the eyes13 of the rods through apertures 14 in the outer sides of the pistons.The connections of the rods with the cranks 10 are of any usual orapproved character.

15 is a casing bolted to the open ends of the cylinders, entirelyinclosing the cranks and rods and keeping dust from said parts and fromthe cylinders, their valves and pistons. One half or portion 16 of thecasing is fixed, carries bearings 17 for the shaft 2, and is adapted tobe attached to the vehicle, thus forming the support for the pump-shaft.The other portion 18 of the crank-casing is removable to give access tothe parts. The other ends of the cylinders are coveredbya valveplate 19and head 20, which are bolted in place. Opposite or in each cylinder 7the plate is formed with air ingress and egress ports 2l and 22 andcorresponding inn-er and outer valve-seats 23 24. Suction an d deliveryvalves 25 and 2G rest on said seats, being mounted on pins 27 28, iiXedin bridges 29, which are cast with the plate and extend across theports. The pin 27 has an interior head, between which and the valve isconiined a spring-washer 30, acting to normally hold the valve on itsseat, but yielding inward to release the valve and admit air when thepiston moves away from the valves. On the outer end of the pin isalock-nut 31, by which the pin, when once adjusted in the bridge 29 so asto bring the proper spring-pressure to bear on the valve, may besecured. The valve 26 and its washer 30 are mounted on the outer end ofthe pin 28, and are adjusted by a nut 32,.secured byla lock-nut 33. Inthe head 2O are formed air-passages 34 and 35, the former leading fromthe atmosphere to the suctionvalve of each cylinder and the latterleading from the delivery-valve of each cylinder to the air-reservoir.The former communication is effected by a pipe 36, which extends upwithin or above the vehicle or to any point free or comparatively freefrom dust, while communication of the passage 35 with the reservoir ishad through a pipe 37.

As the pump-shaft 2 is rotated by the mechanism already referred to, thepistons 8 alternately draw in atmospheric air through the valves 25 anddeliver it through the valves 26 to the air-reservoir, two cylindersfull of air being compressed for each revolution of the shaft.

The above -described construction offers several advantages, the mostimportant of which are lthat the cylinders,pistons, rods,and cranks arecompletely inclosed; the inclosin gcasing can be partly iilled with oil,which will lubricate all of the working parts, including the pistonsWithout further attention; the

single-acting pumps need no packing; the pressure on the pump-shaftbeing always in one direction on the journals there is no difiicultywith any slack that may occur; the valves being in the cylinder-headminimize the clearance and consequently give the pump more capacity; andthe pump being self-contained is easily put in any position and is notliable to be put out of line.

The compressed-air reservoir is shown at 38, consisting of a strongcasing, such as a cylinder of boiler-iron, capable of containing withsafety a normal pressure of, say, thirty pounds, or other desiredamount. Vhen this pressure is attained, the brakeman may cause the pumpto cease operation, through devices hereinafter described, but in orderthat this pressure may not by inattention be exceeded, and to relievethe motive power of the vehicle of unnecessary work in operating theparts of the pump, (even if the latter be prevented in a well-knownmanner from further compressing air,) I provide means for automaticallydisconnecting the pump entirely from the vehicle-axle as soon as thenormal pressure in the reservoir has been reached, said means beingoperated by the 'air from the reservoir.

The means whereby the reservoir-air may control the mechanicalconnection between the pump and axle can take a variety of forms withoutdeparting` from my invention, but I prefer that which I will nowdescribe, comprising a huid-pressure device operated byreservoir-pressure and controlling the mechanical connections betweenthe axle and pump.

39 is a cylinder or casing, which I will term a stop-cylinder, one sideof which is in constant communication with the reservoir through a pipe40, and which is provided with a piston 41, adapted to be acted upon andactuated by the pressure from the reservoir through the pipe 40. Theseparts constitute the fluid-pressure device above referred to. A spring42 acts upon said piston in the opposite direction, and its strength isof such predetermined amount that it will overcome said pressure andhold the parts in the position shown in full lines in Fig. 2, (in whichposition the pump-shaft and axle are connected, as hereinafterdescribed,) until thev normal pressure of thirty pounds in the reservoirhas been reached. Then the spring 42 will be overcome and the piston 41moved from its normal position (shown in Fig. 2) to the opposite end ofthe cylinder. The mechanical connections between the pump or compressorand its motor comprise a clutch, by which term I intend any means forconnecting the compressor with or disconnecting it from the motor. Saidclutch is preferably constructed and operated as follows: 44 is a stemcarried by the piston 41 in line with the pump-shaft 2, and adapted tomove longitudinally a stem 45, mounted in said shaft. The inner end ofthis stem is connected with a cross pin or bar IOO IIO

` the shaft 2.

46, fitted and adapted to play in a slot 47 in Mounted loosely on theshaft is the Wheel 5, already referred to, having on the inner face ofits hub projections or shoulders 48, with which engages the pin 46, Fig.3, when in its Outer position. 49 is a spring in the end of the shaft 2and adapted to press and hold outward, until overcome by the airpressureon the piston 41, the stem 45 With its pin 46. It Will noW be seen thatwhen the reservoir 38 has been charged to its maximum and normalpressure the movement of the parts 41, 44, and 45 will carry the pin 46in- Ward out of engagement With the projections 48 of the Wheel'5,thereby leaving the latter loose on the shaft 2 and free toV rotateunder the operation of the chain 6 Without turning the shaft of the pumpor operating the latter. The parts remain in this inoperative positionuntil by the expansion of the reservoir-air for braking purposes, ashereinafter described,

Vthereservoir-pressure on one side of the piston 41 is reduced below thecounter-pressure of the sprin'gj42 on the other side, whereupon the stem45 Will be released and the spring.

49'Will carry the' pin 46 into engagement With the constantly-rotatin gprojections 46. The pump Will thereby beset in operation and thereservoir pressure restorred to'normaLWhereupon the pin 46 Will be againdisengaged and the pump Will be stopped.

- It is necessary for the Vquick andpositive disengagement of the pin 46from shoulder 48 that the pressure Which actuates the piston 41 bemomentarily retained at a point in excess of that necessary to overcomethe counter-pressure of the springs. i The friction of the shoulders48Aagainst the pin' 46 While driving the shaft 2 Will effect this untilthe'revolution of said shaft-shall bring .the cranks to the position ofpassing their centers, at Which timev the pump-piston atV the end of thecompression stroke will bel returned by the expansion of the airsufliciently to throu the' crank-shaft ahead, and thus'momentarilyrelease the pin46from'the shoulders 48, so that the excess or banked-uppressure acting on piston 41 will quickly carry pin 4,6 clear ofshoulders 48. It is equally necessary that the positive and quickengagement of the pin46 With shoulders 48 should be made,'and'to assurethis the shoulders 48 should be preferably'tWo (2) in number, thusadmitting of a partial revolution ofthe Wheel before the engagement ispermitted.

Whether the compressed air supply be maintained as above described or byany other equivalent or preferred means, l have provided an improvedvalve for controlling it and applying it for braking purposes, to WhichlWill nOW, refer in detail. Vis a valve, of which 50 is the casing,preferably of cast Vmetal,`containing the air-controlling valves proper.Said casing has a main chamber 51, with which may be caused tocommunicate a chamber 52connected bya pipe 53 with the reservoir, achamber 54, connected by a pipe 55 With the brake-cylinder, and anexhaust-chamber 56, communicating by a duct 57 with the atmosphere. Thecommunications of these three chambers With the chamber 51 arecontrolled, respectively, by spring-actuated valves 58,59, and 60,opening in directions'away from the main chamber and having stems orprojections 61, 62, and 63 extending into the latter. The valves areguided in their movements by these stems and by outer stem 64, slidingin closing-plugs 65, screwed into the outer ends of the severalchambers.

66 is the brake-cylinder, of the usual character, With Whichcommunicates the pipe 55, as aforesaid, and having a piston 67, the rod68of which is connected With and operates the brake-shoes, one of Whichlatter is indicated at 69 and its Wheel at 70.

When the 'valves 58 and 59 are both open, the compressed air from thereservoir Will be immediately admitted to thevbrake-cylinder, the brakesapplied, and the vehicle stopped. Whenthe valve 58'is` reseated andvalves 59 and opened, the air from the brake-cylinder Will be permittedto' exhaust' through` the aperture 57 and the spring 71 of thebrakepiston Will release the brakes. These valve movements areconveniently effected by a cam 72, mounted in the chamber 51 upon atransverse rock-shaft 73, the latter being actuated at Will bythebrakeman through a handle 74, conveniently situated, (say at the frontof the vehicle), a rod 75, and a crank-arm 76, fixed on thecam-shaft.The cam is formed With a linger or projection 77, situated between andadapted to force outward either of the valvestems 61 or 63, with aconsequent opening of its`valve, and With projections 78 and 79,eitherof which is adapted to force outward the stem 62and open the valve59, according to the direction in Which the handle 74 ismoved and thecam rocked. The projections 78 and 79 are so arranged relative to thefinger 77 that the linger Will operate iirst to open its valve by aslight movement of the handle 7 4, (say to the notch 8O or 81 of thehandle-controlling`segment,) While a farther4 movement of the' cam, (thehandle being moved to the notch- 82 or 88,) will keep the rst valve openIOO IIO

and cause the projection 78 or 79 to open the While shifting it to thenotch 83 Will release them. c

The movement of the handle to the notch 80 will open the reservoir tothe chamber 51, and

to the notch 81 Will open the latter .chamber to the atmosphere, Withoutin either case` affecting the brakes.- But these movements effect other`useful purposes, as Will now be described.

with which communicates a pipe 85, leading to an opening 86 in thestop-cylinder 39. ,It

is obvious'that the communication ,maybe v 13o -84 is an opening intothe main chamber 51,

directly from the brake-cylinder to the stop or controlling cylinder 30.This latter opening 8G is at the opposite side of the piston 41 from thepipe 40, the consequence of which is obvious. The parts being in theposition the reverse of that shown in Fig. 2 with the pump out ofoperation, and it being desired to attain a reservoir air-pressure abovethe normal, the handle 74 is moved to the notch 80. This will open thevalve 58, but not the valve 59, and will admit reservoir-pressure intothe stop-cylinder on the same side of the piston as the spring. The twoacting together immediately overcome the pressure in the pipe 40, causethe parts 46 48 of the clutch to engage, and enable the wheel 5 tooperate the pump. This operation will now continue indefinitely, but maybe stopped by moving the handle 74 to the notch 81, whereupon the valve58 will close and the valve 60 be opened, placing the stop-cylinder 39in communication with the atmosphere. The spring 42, unaided, will beimmediately overcome by the reservoir pressure in pipe 40 and the partsof the clutch unlocked, disconnecting the pump from the axle. l

Exhaust-valve 60 opens with the pressure, and, as shown, the valveactsas a safety or relief for the pressure thrown in to brake-cylinder.The other valves are held seated by the pressure in addition to theirrespective springs. Vhen the communicationfrom the operating valve tothe stop-cylinder is through the brake-cylinder, the pump will onlystart when there has been sufficient air drawn out of the reservoir andthrown into the brakecylinder.

lt will thus be observed that the operation of the pump is under thecontrol of the brakeman irrespective of any operation of the brakes. Atthe same time the air-supply may be entirely kept up to thepredetermined normal pressure by that operation of the pump whichautomatically occurs when the brakes are applied, as already explained,the pump being so proportioned and geared that it will restore to thereservoir the full pressure of thirty pounds in the distance traveled bythe car while being stopped. The amount of air withdrawn from thereservoir to apply the brakes being thus pumped into the reservoir whilethe brakes are being applied, the air supply and pressure is practicallyinexhaustible, and the operation of the pump at this time assists instopping the car. A safety-valve 87 is placed on the reservoir andarranged to carry such maximum pressure as may be advisable. Theconstant communication between the chamber 51 and the stop-cylinderimmediately causes the piston 41 to be balanced, so far as air-'pressureis concerned, upon the opening of the valve 58. This will leave thespring 42 free and cause the pump to be started, whatever be thepressure in the reservoir. After applying the brakes the camfinger maybe returned to its normal central position, allowing all valves to closeand leaving the brakes on and the pump in operation. A return movementof the finger against the valve-stem 63 will exhaust the stop-cylinderand release and stop the pump, as already eX- plained, without releasingthe brakes; but notwithstanding this independent capacity of operationof the pump and brakes, the application of the latter is alwaysaccompanied by the starting of the former.

The placing of the operation of the pump under the direct control of themotorman or driver not only simplifies the mechanism, but does away withthe liability of automatic mechanism causing a failure of the brakes tooperate when most needed.

The failure of the only automatic mechanism used in the above-describedsystem will be an error on the safe side, and if the pump should run toolong the only harm would be the waste of air through the safetgf-valve.

What is claimed is-n 1. In a fluid-pressure brake, the combination of apump, a reservoir a brake-cylinder having communication therewith, acontrolling-cylinder determining the operation of the pump, and asuitable valve device independently controlling communication betweenthe reservoir and the brake-cylinder and between the reservoir andcontrollingcylinder, as set forth.

2. In a fluid-pressure brake, the combination of a pump, a reservoir abrake-cylinder having communication therewith, a controlling-cylinderdetermining the operation of the pump, and a suitable valve deviceindependently controlling communication between the reservoir andcontrolling-cylinder, and between the reservoir, brake-cylinder andcontrolling-cylinder, as set forth.

3. In a fluid-pressure brake, the combination of a pump, a reservoir abrake-cylinder having communication therewith, a controlling-cylinderdetermining the operation of the pump, and a suitable valve deviceindependently controlling communication between the reservoir and thebrake-cylinder, between the reservoir and controlling-cylinder, andbetween the brake-cylinder and exhaust, as set forth.

4. In a duid-pressure brake, the combination of a pump, a reservoir abrake-cylinder having communication therewith, a controlling-cylinderdetermining the operation of the pump, and a suitable valve deviceindependently controlling communication between the reservoir and thebrake-cylinder, between the reservoir and controlling-cylinder, andbetween the controlling-cylinder and exhaust, as set forth.

5. In a huid-pressure brake, the combination of a pump, a reservoir abrake-cylinder having communication therewith, a controlling-cylinderdetermining the operation of the pump, and a suitable valve deviceindependently controlling communication between the reservoir and thebrake-cylinder, between the reservoir and the controlling-cyl- IOOinder, and between the brake-cylinder, controlling-cylinder and eXhaust,as set forth.

6. In a fluid-pressure brake, the combination of a pump, a reservoir abrake-cylinder having communication therewith, a controlling-cylinderdetermining the ope'ration of the pump, and having two connections withthe reservoir and a suitable valve device controlling communicationbetween the reservoir and brake-cylinder and also one of saidconnections with the controlling-cylinder, as set forth.

7. In a fluid-pressure brake, the combination of a pump, a reservoir abrake-cylinder havingcommunication therewith, a controlling-cylinderdetermining the operation of the pump, and a suitable valve devicecontrolling communication between the reservoir and brake-cylinder, andindependently controlling communication between the reservoir,controlling-cylinder and exhaust, as set forth.

8. In a fluid-pressure brake, the combination of an air pump orcompressor, connections from the same to an actuating means such as avehicle-axle, a reservoir supplied by said pump, means for regulatingthe application of the fluid-pressure to the brake, a fluid-pressuredevice having two independent communications with the reservoir andcontrolling the connection of the pump with its actuating means, a valvein one of said independent connections to cause a movement of saiddevice independent of the application of the brake, and the othercommunication constantly open to the fluid-pressure device as set forth.

9. In a fluid-pressure brake, the combination of a brake-cylinder andpump, a reservoir in communication with the same, a iiuidpressure devicecontrolling the action of thepump and having communication at one sidewith the reservoir, a passage from the other side of said device to thereservoir, and a valve device controlling said passage andcommunications whereby on the admission of huid-pressure to thebrake-cylinder it is also admitted to the said other side of thepressure device and also independently controlling said passage,substantially as set forth.

l0. In a fluid-pressure brake, the combination with a pump andreservoir, of a stopcylinder and piston,communications between thereservoir and stop-cylinder on opposite sides of said piston, a valvecontrolling one of said communications independent of the application ofthe brake and the other communication constantly open to thestop-cylinder, as set forth.

ll. In a fluid-pressure brake, the combination with an air-compressorand means for actuating the same, of a reservoir supplied thereby, abrake apparatus or cylinder, a passage leading from the reservoir to thebrakecylinder, avalve controlling the said passage, a fluid-pressuredevice connected with the communications with the reservoir andcontrolling said clutch, a valve in one of said vcommunications to causea movement of said device independent of the application of the brakeand the other communication constantly open to the fluid-pressuredevice, as set forth.

13. In a fluid-pressure brake apparatus a huid-controlling valve,comprising three independent valves and a cam arranged to engage eitherone of two of said valves, and either of said two valves and the othervalve, substantially as set forth.

l-l. In a huid-pressure apparatus a fluidcontrolling valve, comprisingthree valves proper, and a cam having three lingers, one finger foractuating either one of two of said valves, the other two fingers foroperating the other valve in opposite movements of the cam,substantially as set forth.

15. The combination with the reservoir brake-cylinder and exhaust, of avalve comprising a casing having three ports, a valve controlling eachof the same and adapted by their operation to place said reservoir andbrake-cylinder in communication and to place the brake-cylinder andexhaust in connection, a cam common to said valves and adapted toactuate them, and means for turning the cam, substantially as set forth.

16. In a huid-pressure brake the combination with a brake-applyingmeans, of a compressor or pump communicating with the same, mechanicalconnections for actuating the pump from a suitable motor such as thevehicle-axle, a fluid-pressure device controlling said mechanicalconnection, and avalve controlling the communication between thecompressor and the brake-applying means and also independentlycontrolling said fluidpressure device, said valve comprising a casing,three independent valves within the same and a cam for actuating saidvalves at predetermined times, substantially as set forth. In witnesswhereof I have hereunto signed my name in the presence of two witnesses.

HENRY L. HOWE. Witnesses Gno. H. GRAHAM, MAX O. BEARD.

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